package com.shun.auth.service;

import cn.hutool.core.codec.Base64Encoder;
import lombok.extern.slf4j.Slf4j;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.Map;
import java.util.Random;

/**
 * 图片工具
 *
 * @author clerver
 * @since 2021-09-29
 */
@Slf4j
public class SliderService {

    public final static int targetWidth = 55;//小图长
    public final static int targetHeight = 45;//小图宽
    public final static int circleR = 8;//半径
    public final static int r1 = 4;//距离点

    /**
     * 生成小图轮廓
     *
     * @return int[][]
     */
    private static int[][] getBlockData() {
        int[][] data = new int[targetWidth][targetHeight];
        double x2 = targetWidth - circleR; //47
        //固定在中间
        double h1 = circleR + 0.5 * (targetWidth - 3 * circleR - r1);
        double po = Math.pow(circleR, 2); //64
        double xbegin = targetWidth - circleR - r1;
        double ybegin = targetHeight - circleR - r1;
        //圆的标准方程 (x-a)²+(y-b)²=r²,标识圆心（a,b）,半径为r的圆
        //计算需要的小图轮廓，用二维数组来表示，二维数组有两张值，0和1，其中0表示没有颜色，1有颜色
        for (int i = 0; i < targetWidth; i++) {
            for (int j = 0; j < targetHeight; j++) {
                double d2 = Math.pow(j - 2, 2) + Math.pow(i - h1, 2);
                double d3 = Math.pow(i - x2, 2) + Math.pow(j - h1, 2);
                if ((j <= ybegin && d2 < po) || (i >= xbegin && d3 > po)) {
                    data[i][j] = 0;
                } else {
                    data[i][j] = 1;
                }
            }
        }
        return data;
    }

    /**
     * 有这个轮廓后就可以依据这个二维数组的值来判定抠图并在原图上抠图位置处加阴影,
     *
     * @param oriImage      原图
     * @param targetImage   抠图拼图
     * @param templateImage 颜色
     * @param x
     * @param y
     */
    private static void cutByTemplate(BufferedImage oriImage, BufferedImage targetImage, int[][] templateImage, int x, int y) {
        int[][] martrix = new int[3][3];
        int[] values = new int[9];
        //创建shape区域
        for (int i = 0; i < targetWidth; i++) {
            for (int j = 0; j < targetHeight; j++) {
                int rgb = templateImage[i][j];
                // 原图中对应位置变色处理
                int rgb_ori = oriImage.getRGB(x + i, y + j);
                if (rgb == 1) {
                    targetImage.setRGB(i, j, rgb_ori);
                    //抠图区域高斯模糊
                    readPixel(oriImage, x + i, y + j, values);
                    fillMatrix(martrix, values);
                    oriImage.setRGB(x + i, y + j, avgMatrix(martrix));
                } else {
                    //这里把背景设为透明
                    targetImage.setRGB(i, j, rgb_ori & 0x00ffffff);
                }
            }
        }
    }

    private static void readPixel(BufferedImage img, int x, int y, int[] pixels) {
        int xStart = x - 1;
        int yStart = y - 1;
        int current = 0;
        for (int i = xStart; i < 3 + xStart; i++)
            for (int j = yStart; j < 3 + yStart; j++) {
                int tx = i;
                if (tx < 0) {
                    tx = -tx;
                } else if (tx >= img.getWidth()) {
                    tx = x;
                }
                int ty = j;
                if (ty < 0) {
                    ty = -ty;
                } else if (ty >= img.getHeight()) {
                    ty = y;
                }
                pixels[current++] = img.getRGB(tx, ty);
            }
    }

    private static void fillMatrix(int[][] matrix, int[] values) {
        int filled = 0;
        for (int i = 0; i < matrix.length; i++) {
            int[] x = matrix[i];
            for (int j = 0; j < x.length; j++) {
                x[j] = values[filled++];
            }
        }
    }

    private static int avgMatrix(int[][] matrix) {
        int r = 0;
        int g = 0;
        int b = 0;
        for (int i = 0; i < matrix.length; i++) {
            int[] x = matrix[i];
            for (int j = 0; j < x.length; j++) {
                if (j == 1) {
                    continue;
                }
                Color c = new Color(x[j]);
                r += c.getRed();
                g += c.getGreen();
                b += c.getBlue();
            }
        }
        return new Color(r / 8, g / 8, b / 8).getRGB();
    }

    /**
     * 读取本地图片，生成拼图验证码
     * 返回生成的抠图和带抠图阴影的大图 base64码及抠图坐标
     *
     * @return Map<String, Object>
     */
    public static Map<String, Object> createImage(BufferedImage oriImage, Map<String, Object> resultMap) {
        try {
            Random random = new Random();
            //X轴距离右端targetWidth  Y轴距离底部targetHeight以上
            int widthRandom = random.nextInt(oriImage.getWidth() - 2 * targetWidth) + targetWidth;
            int heightRandom = random.nextInt(oriImage.getHeight() - targetHeight);
            log.debug("原图大小x:{},y:{},随机生成的坐标X:{},Y:{}", oriImage.getWidth(), oriImage.getHeight(), widthRandom, heightRandom);
            BufferedImage targetImage = new BufferedImage(targetWidth, targetHeight, BufferedImage.TYPE_4BYTE_ABGR);
            cutByTemplate(oriImage, targetImage, getBlockData(), widthRandom, heightRandom);
            resultMap.put("bigImage", "data:image/jpg;base64," + getImageBASE64(oriImage));//大图
            resultMap.put("smallImage", "data:image/jpg;base64," + getImageBASE64(targetImage));//小图
            resultMap.put("xWidth", widthRandom);
            resultMap.put("yHeight", heightRandom);
        } catch (Exception e) {
            log.debug("创建图形验证码异常", e);
        } finally {
            return resultMap;
        }
    }

    /**
     * 读取本地图片，生成拼图验证码
     * 返回生成的抠图和带抠图阴影的大图 base64码及抠图坐标
     *
     * @return Map<String, Object>
     */
    public static Map<String, Object> createImage(File file, Map<String, Object> resultMap) {
        try {
            BufferedImage oriImage = ImageIO.read(file);
            return createImage(oriImage, resultMap);
        } catch (IOException io) {
            log.error(io.getMessage());
        } finally {
            return resultMap;
        }
    }

    /**
     * 读取网络图片，生成拼图验证码
     * 返回生成的抠图和带抠图阴影的大图 base64码及抠图坐标
     *
     * @return Map<String, Object>
     */
    public static Map<String, Object> createImage(String imgUrl, Map<String, Object> resultMap) {
        log.debug("imgUrl:{}",imgUrl);
        try {
            URL url = new URL(imgUrl);
            BufferedImage bufferedImage = ImageIO.read(url.openStream());
            return createImage(bufferedImage, resultMap);
        } catch (IOException io) {
            log.error(io.getMessage());
        } finally {
            return resultMap;
        }
    }

    /**
     * 图片转base64
     *
     * @param image
     * @return String
     */
    public static String getImageBASE64(BufferedImage image) throws IOException {
        ByteArrayOutputStream bao = new ByteArrayOutputStream();
        ImageIO.write(image, "png", bao);
        byte[] imagedata = bao.toByteArray();
        String base64Image = Base64Encoder.encode(imagedata).trim().replaceAll("\r|\n", "");
        return base64Image;
    }
}